Although many iPhone users experience better battery life after the iOS 4.0 update, a number of users have reported decreased battery life after updating. A sampling of reports from Apple’s Discussion boards:

Graham Powell1: “Upgraded 3G last night and bettery useage is through the roof. Getting less than an hour from full charge, phone very very hot.”

vatkins1906: “[…] Horrible Battery Life after iOS 4. Before going to bed my 3GS had 100% battery power. With no applications running in the background, I awoke with the phone completely dead! Before installing iOS 4 it would be at around 95%.”

Fixes

Check Internet tethering. Some reports indicate that the iPhone may be persistently attempting to establish a tethering connection, thereby draining the battery. Navigate to Settings > General > Network and tap Internet Tethering, then tap “cancel” if you it is trying to connect, or turn off tethering altogether. You may need to turn Wi-Fi off then back on to stop the tethering connection attempts.

Bad apps to blame? Anecdotal evidence suggests that apps incompatible with iOS 4.0 or otherwise problematic under the new release can cause battery drain issues. Backup your iPhone in iTunes, then delete apps from the device in groups (you can always sync them back from iTunes later). After each group, restart your iPhone and check for the battery drain problem. Via this method, you can isolate the problematic app and remove it permanently.

Also, make sure all apps are up to date; developers have released a flurry of iOS 4.0-compatible app editions in the past few days.

Calibrate the battery. Fully charge your iPhone, then allow it to drain until completely empty (device powers off on its own and displays a spinning progress indicator). Then recharge your phone and check for excessive battery drain.

Close open Safari windows. One iOS application that consumes memory and processor time (and therefore battery life) in the background is Safari. Close all unused windows in the application by pressing the page switch button in the lower right portion of the screen then clicking the X at the top left of each page.

Restore, but not from a backup (use as a last resort). As is the case with some other iOS 4.0 problems, one less-than-ideal fix for the battery drain issue involves restoring the iPhone as a new device rather than from a backup. It appears that bad holdover data from iPhone backups can cause excessive battery use. Restoring as a new phone will delete contacts and other data, but may resolve this problem.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Check Location Services It appears that overactive location services usage can result in poor battery life. Specifically, apps that use location services in the background can quickly drain the battery.

To check location services usage on an app-by-app basis, navigate to Settings > General > Location Services. Turn location services off for all applications, then turn them back on for desired apps one by one or in groups. Via this procedure, you can identify which app’s use of location services is draining battery. Alternatively, you can temporarily turn off location services altogether and check for increased battery life.

Mail Stalls on “Checking for Mail”; Cannot Receive or Send Mail

A number of users have reported an issue in which the Mail app hangs indefinitely when checking for new messages after the update to iOS 4.0. In these cases, the “checking for mail” and the spinning progress indicator display persistently, never advancing to actually receiving mail, or the check for mail button produces no action.

This issue occurs with MobileMe, IMAP, POP and Exchange accounts.

Fixes

Restart mail. If you are using a device that allows multitasking, double-tap the home button to bring up the list of currently running applications. Hold the Mail icon until it begins to wiggle, then tap the small red circle to close it. Relaunch Mail and check your mail.

Download configuration file. If you are having this problem with an Exchange account, you may need to install a configuration profile from Apple that increases the amount of time the iOS 4 device will wait for the Exchange Server to respond to its sync requests. See this knowledge base document for more information.

Turn airplane mode on then back off. Go to Settings and turn Airplane Mode on then back off.

Reboot. Simply rebooting your iPhone, iPad or iPod touch by holding down the sleep/wake button (on top of the device) for several seconds, until power off slider appears, then powering the unit back on can temporarily resolve this issue.

iPhone 3G Slowness

A number of iPhone 3G users have experienced a significant degradation in performance after the iOS 4.0 update. iPhone 3GS users generally report across-the-board performance improvements with the new update, but original iPhone 3G users have reported slow app launching, delayed reactions to taps, and generally poor interface responsiveness.

Fixes

Perform a “hard reset.” Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot. Some users have (oddly enough) reported that performing two hard resets resolves the slowness issue.

Restore, but not from backup. It appears that bad holdover data from iPhone backups can cause performance problems. Restoring as a new phone will delete contacts and other data, but may resolve this issue.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Free up space. Make sure that your iPhone has at least 10% of its available memory free. OS X-based systems, such as iOS 4.0, may require some free space to operate properly.

Close open Safari windows. One iOS application that consumes memory in the background is Safari. Close all unused windows in the application by pressing the page switch button in the lower right portion of the screen then clicking the X at the top left of each page.

Error 29 When Updating

Some users have reported an issue in which iTunes displays the error message “The iPhone “name of iPhone” could not be restored. An unknown error occurred (29)” when attempting to update to iOS 4.0, or perform a restore on an iOS 4.0 device.

This issue appears to affect primarily users who have replaced their batteries or some other hardware components through a service such as iFixit. Error 29 indicates a hardware issue, which means that iOS 4.0 may be (accurately or not) triggering some compatibility issues with after-market add-ons or replacements.

Fix

Some users have been able to resolve this issue via the use the utility iRecovery. Instructions are here.

No 3G, EDGE or MMS Service

A number of iPhone users have reported loss of cellular data access (3G or EDGE) after the update to iOS 4.0.

Fixes

Reset all settings. Try this first. On your iPhone, select Settings, then Reset, then Reset All Settings. This will result in the loss of data created since your last backup, but may solve the problem.

Restore, but not from a backup. One less-than-ideal fix for this issue involves restoring the iPhone as a new device rather than from a backup. It appears that bad holdover data from iPhone backups can cause loss of data access. Restoring as a new phone will delete contacts and other data, but generally resolves this problem.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Download new carrier settings. On your iPhone, go to Settings > General > About. If prompted for a carrier settings update, install it.

“Troubleshooting MMS” states: “you may encounter the following issues: You are unable to receive MMS messages; […] A red exclamation mark appears next to MMS messages you send” and offers a number of fixes.

iPod App on iPhone Crashes

Some users have reported that the iPod app on the iPhone crashes after the iOS 4.0 update. These users report that the app crashes on launch, or while it is running in the background. In other cases, songs will simply stop playing midway, although the iPod app does not crash completely.

Don’t sync podcasts. In some cases, it appears that problematic podcast files may be to blame for this issue. Deselect podcasts for syncing in iTunes, then re-sync your iPhone.

Switch to manual sync. After performing the aforementioned fixes, try switching to manual syncing in iTunes. To do so, select your iPhone from the left-hand pane in iTunes, then click the Summary tab and select “Manually manage music and videos”.

Restore, but not from backup. It appears that bad holdover data from iPhone backups can cause this problem in some cases. Restoring as a new phone will delete contacts and other data, but may resolve this issue. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

iPhone Reboots/Resets During Phone Calls

Some users have reported an issue in which the iPhone repeatedly reboots in the middle of phone calls. Afflicted users reported that the phone simply restarts anywhere from 1 to 5 to 10 minutes into calls.

Potential fixes

Reset network settings. On your iPhone, open Settings, then navigate to “General” in the left-hand pane. Scroll down and tap Reset, then select “Reset Network Settings.” This will delete any stored WiFi passwords and other information, but may result in a more stable connection.

Restore, but not from backup. Although this fix is not universally successful, some users have reported relief via restoring the iPhone as a new device rather than from a backup. It appears that bad holdover data from iPhone backups can cause the reboot problem. Restoring as a new phone will delete contacts and other data, but may resolve this problem.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

No Wi-Fi

A few users have reported loss of iPhone Wi-Fi connectivity after the update to iOS 4.0. In these cases, the Wi-Fi option in the iPhone’s Settings app may be grayed out.

Potential fixes

Turn router off then on Try turning your wireless router off then back on.

Change or turn off wireless security You may want to try toggling the settings on your wireless router, switching from WPA to WEP or vice versa, or, as a last resort, turning wireless security off altogether. For AirPort routers, this can be accomplished with the AirPort Admin Utility. For other routers, this can usually be accomplished by accessing the router’s configuration page — open a browser and enter the address 192.168.1.1.

Reset network settings on iPhone. On your iPhone, open Settings, then navigate to “General” in the left-hand pane. Scroll down and tap Reset, then select “Reset Network Settings.” This will delete any stored WiFi passwords and other information, but may result in a more stable connection.

Restore, but not from a backup. One less-than-ideal fix for this issue involves restoring the iPhone as a new device rather than from a backup. It appears that bad holdover data from iPhone backups can cause loss of data access. Restoring as a new phone will delete contacts and other data, but generally resolves this problem.

To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”

Update Stuck on Backup or Extremely Slow

Several users have reported an issue in which the iPhone and iPod touch become indefinitely stuck on the backup phase of the iOS 4.0 Update. Other users report that the backup process is inordinately slow after the update, taking up to 3 hours in some cases.

Fixes

Disable network connection. In some cases, simply disabling your network connection (turning off AirPort or unplugging your Ethernet cable) will resolve the slow or stuck backup phase. It appears that iTunes performs some data network data transfer during the backup process which can, for unknown reasons, take an extremely long time or become stalled.

Restore instead of update. Backup your iPhone or iPod touch, then perform a restore process instead of using the check for update function. This may allow the iPhone or iPod touch to successfully receive the iOS 4.0 update, after which sync processes should occur at normal speed.

Switch USB ports. Try switching your iPhone or iPod touch to a different USB port. In particular, if you are using a hub or other intermediary device, try connecting the device directly to your computer.

Sync Errors

Some users have reported an issue in which iPhones fail to sync with iTunes 9.2. In these cases, sync attempts result in the error message “The iPhone (name) cannot be synced. A duplicate file name was specified.” This problem may be accompanied by duplication of music and other media files.

Fixes

There are two potential fixes for this issue:

Remove iToner or updateAs noted in our previous report on iTunes 9.2 syncing problems, appears that the presence of Ambrosia Software’ iToner software may cause problems with syncing. Navigate to ~/Library/iTunes/iTunes Plug-insand/Library/iTunes/iTunes Plug-ins (the Library folders inside your user folder and at the root level of your startup drive) and look for a file called iTonerSupport.bundle. Remove it, then restart, and check to see if iPad syncing occurs more quickly.

Reader Interactions

Show 18 Comments

I am VERY upset with the new update for my ipod touch! I lost EVERYTHING off my ipod trying to mess with upgrading, which has NEVER happened before. Once everything was back on my ipod all of my apps are being ridiculously slow! This is quiet annoying, if anyone knows how to fix this please let me know! Thank you.

My experience: some iTunes installs are missing iPhone drivers, leaves the iPhone in a Recovery Loop error 29. I Uninstalled iTunes (10.0), installed iTunes 10.1, reconnected the iPhone and it was able to communicate. I did have to use TinyUmbrella to kick it out of the Recovery Loop. (/|) Peace

I’m running OS4 on an iPod touch 2g. Let me explain something. I have NEVER had as many crashes and failures in my life with this device until this update. Every app has immense lag if I have used another app before it. I literally have to restart my device if I am going to use another app. It is even a problem for this itouch to even make a valid connection with my ihome!! This is absurd. If a bunch of hackers can make a better OS (jailbreaking) for a device that YOU created apple then you have the worst programmers I have ever seen in my entire life. That is shameful that people living in their moms basement can make a better operating system that has more features and is more efficient than your junk. Only reason I’m not smashing this into pieces and mailing it to you is because I’m going to use THEIR OS not yours. Good Luck Have Fun.

I’m running OS4 on an iPod touch 2g. Let me explain something. I have NEVER had as many crashes and failures in my life with this device until this update. Every app has immense lag if I have used another app before it. I literally have to restart my device if I am going to use another app. It is even a problem for this itouch to even make a valid connection with my ihome!! This is absurd. If a bunch of hackers can make a better OS (jailbreaking) for a device that YOU created apple then you have the worst programmers I have ever seen in my entire life. That is shameful that people living in their moms basement can make a better operating system that has more features and is more efficient than your junk. Only reason I’m not smashing this into pieces and mailing it to you is because I’m going to use THEIR OS not yours. Good Luck Have Fun. Apple sucks.

I have had a couple of issues with sync’ing ipad notes to Outlook/Exchange 2007. My initial problem was caused by having a subfolder in my Notes folder in Outlook. Once I deleted that subfolder, notes sync’d between the Outlook and my iPad flawlessly until…

I started having problems again. After finding some information about possible problems with the iTunes upgrade, I went through the downgrade process provided on this site. But that didn’t fix the problem. I tried resetting sync history, resetting the device to factory settings, restoring the device (from itunes) all to no avail.

I looked at my notes list again in Outlook and realized I had a note with no text on the first line (in essence, a note with no “title”). Once I deleted that note, the sync started working again!

It appears that the sync is very picky about the structure of the data.

Any idea on how I will fix my ipod touch.. Before I upgrade it into IOS 4 everything is fine but now I still can connect to wifi but everytime I check my FB or ym account there was a message that no connection.. please help.. I already done with reset settings and reset network but still I can’t connect.

When I open the app store in my 3GS and go to download an app, and the “FREE” or “$x.xx” button is not even on the screen. Completely disappeared. My phone has been recently updated and i have no idea what to do. Please help.

It takes me upto 3 attempts to leave a post on someones wall on the facebook app, my iPod function constantly freezes, it took me over 12 hours to back up my iPhone 3G before I could even update the software again and it is STILL useless ……………….. I was considering my upgrade to the iPhone 4 but now I am wondering why I should fork out more money only to be faced with more problems!!

Making 3G iphones almost unusable by updating the software, i.e. giving it a battery life of 12 houers and slowing it down, so that not even a phone call can be placed without hassle, is definitely helping Apple to sell 4G phones now. Yet, they should provide an opportunity to reload iOS3.1.3 for those not willing to buy a new device every year.

Hey Apple – please give us an option in iTunes to revert to iOS 3.1.3, at least for 3G users. My wifi is gone & battery life is shot. Obviously a lot of unhappy people out there. All iOS4 did was make many phones almost unusable. A half-hour in the freezer will give me a half-hour wifi, then gone! Then to get reasonable battery life need to turn almost every feature off! Not happy Apple.

Thank you so much – tried to upgrade to 4.0.1 today and had what can only be described as a nightmare. Phone locked up and I was left with an iBrick. I tried everything from spoofing the signature servers to RecBoot and more. Your simple tip to disable the network connection worked!

You should not have to turn off your wireless security to get this to work. That is a preposterous suggestion! If that is really the fix, you can have my phone. I am not going to lower my security to use it.